Richard Muller moves along to the 13th century, in which commenting upon Peter Lombard’s Sentences became normative for the study of theology. Even a younger Martin Luther commented upon the Sentences (though not upon the Doctrine of God) and Calvin viewed the work as foundational for Medieval theology.
With that said, I’m skipping a lot of Muller’s treatment of Lombard (and his contemporaries), and how they worked out “the divine attributes”. This is, after all, a “brief” history, and these treatments rely heavily upon various patristic conceptions. Once Aristotle is introduced into the mix, the attributes (and the descriptions of them) take on a different character. It is the language of the “high scholastics” (13th century and following) that carries through into the Reformed Orthodox period.
The scholastic investigation of the relation of faith and reason, theology and philosophy, and of the grounds of theological discourse raised almost immediately—one might well say, necessarily—the fundamental questions underlying the doctrine of God. And it is, conversely, the Christian perception of the essence, attributes, and trinitarian nature of God that most clearly presses these issues of the ways of knowing.
As the fathers after Origen had recognized, God is at once the supreme object of theology and also the most difficult object to know. The medieval scholastic doctrine of God proceeded with the recognition that we cannot know God in the same way that we know things—given that the being or essence of God is not available to sense perception and does not fit into our normal categories of comprehension.
It is also, therefore, not immediately clear how we can say of God the things we wish to say about him: that he is good, just, powerful, and so forth. Likewise, it is not immediately apparent just how the things that faith and revelation tell us about God—that he is good, just, powerful and so forth—fit into our normal rational use of those terms. After all, what God is, the essence of God, is not at all like what we are.
In the immediate context of the scholastic development of the doctrine of God, so often characterized as highly speculative in the modern sense of the term, therefore, there was also a powerful sense of the limits of human comprehension. The point is important to the broader study of the “scholastic” doctrine of God—and we need to return to it in later discussion of late sixteenth- and seventeenth-century scholasticism.
Where Anselm had indicated that the divine is ultimately beyond our comprehension, Albert the Great distinguished carefully between the intellectual attainment of the divine and the creaturely comprehension of God: the former, he commented, was possible, the latter impossible.
A similar, and related, point concerning the scholastic approach to God concerns the intimate connection between the objective statements concerning knowledge of God found in the more systematic or dogmatic expositions of theology and the piety and “subjectivity” of knowledge: a contrast can be made between the more objectivising “outer way” of knowing that moves from sense perception, through a process of rational abstraction, to knowledge, and the “inner way” that moves deeply into the intellect of the knowing subject for its foundations of knowledge.
The latter pattern, more characteristic of Bonaventure than of Aquinas, ought not to be severed from our understanding of scholastic method in theology.
With specific reference to the ways in which God may be known, the scholastics offered a series of “paths,” or viae, that not only describe the rational patterns of gaining some knowledge of God but that also provide categorizations of the divine attributes.
Thus, Alexander of Hales could indicate that God is known per modum positionis and per modum privationis, by way of positive argument and by way of removal or negation: according to the former pattern, we know “what God is,” according to the latter, “what God is not.” The negative path is necessary since, in an ultimate sense, “the divine substance, in its immensity, is not knowable by the rational soul according to a positive understanding, but by a privative understanding.”
There is, moreover, a variant of the positive way, an inward via eminentiae, that moves by way of the image of God in the soul, through intellect, memory, and will, to the knowledge of God as the highest Good and as ultimate Truth.
There is, in fact, a major divide among the medievals on this point: in the Bonaventurean perspective, this model of inward intellectual ascent toward knowledge of God yield not a full but nonetheless an essential knowledge of the divine. Aquinas, on the other hand, stressed the transcendence of God and the necessity of the negative or privative way.
Granting this sense of the limitation of human knowledge of God and the principle of his teacher, Albert, that the intellect can attain to God but cannot ultimately comprehend him, Aquinas concluded that human beings have no natural or purely rational knowledge of God in se, specifically, no ultimate essential or “quidditative” knowledge of God (cognitio Dei quidditativa) apart from grace—and that this is gained by revelation rather than by inward illumination.
Muller, R. A. (2003). Post-Reformation Reformed Dogmatics: The Rise And Development Of Reformed Orthodoxy; Volume 3: The Divine Essence And Attributes (pp. 46–48). Grand Rapids, MI: Baker Academic.
Muller here is setting the stage for some of the larger discussions of the Doctrine of God that became a part of the Medieval discussion. It’s not important to know all of these “ways” in depth, but the terms will re-occur if you continue to look into the history of the Medieval church.